Utilization of nitrogen and energy by Holstein steers fed formaldehyde- and formic acid-treated alfalfa or orchardgrass silage at two intakes

Our objective was to measure the utilization of energy (E) and N by Holstein steers when fed alfalfa and orchardgrass silages offered at 65 and 90 g DM/kg live weight (LW).75 daily. Twelve steers adapted to the Beltsville respiration chambers were assigned to three Latin squares with 42-d periods. Steers in one square had permanent catheters in the portal and two mesenteric veins. Energy and N balance were measured during a 7-d collection of feces and urine that included a 3-d measurement of respiratory exchange. Energy and N variables were not different between catheterized and uncatheterized steers. Apparent digestibilities of DM, OM, CP, neutral detergent solubles and permanganate lignin were higher (P less than .01) and digestibilities of NDF and ADF, hemicellulose and cellulose were lower (P less than .01) for steers consuming alfalfa compared to orchardgrass silage. When fed alfalfa, steers' daily gross energy intake, DE, urine energy, ME, heat production and tissue energy retention were greater (P less than .01) and fecal energy losses were less (P less than .01) than when they were fed orchardgrass. Partial efficiency of ME use for tissue energy (TE) was greater (P less than .01) for steers when fed alfalfa (46.1%) than when fed orchardgrass (35.6%). Apparent ME (kcal/LW.75) required for maintenance of TE was similar for steers when fed alfalfa (133.9) and orchardgrass (131.2) silages. Nitrogen retention (g/d) was 48% greater (P less than .01) for steers when fed alfalfa (30.6) than when fed orchardgrass (20.7). This study demonstrates that steers used ME from alfalfa more efficiently for TE deposition than ME from orchardgrass.     

Effect of exogenous porcine somatotropin administration on nitrogen and energy metabolism in three genotypes of pigs

Effects of exogenous administration of porcine recombinant somatotropin (rpST) on protein gain and metabolic rate were measured in three genotypes (castrated males) of pigs (Pietrain, Duroc and a crossbreed between Dutch Yorkshire and Dutch Landrace). Six pigs of each genotype were assigned at approximately 60 kg to receive pST doses of either 0 (C) or 14 mg (T) administered i.m. twice weekly over 10 wk. Pigs were housed in individual metabolism cages at a room temperature of 20 to 22 degrees C and received feed at 2.6 times maintenance. Protein gain (N x 6.25) was measured over the final 6 wk of the 10-wk test period. For 2 wk in the test period (wk 2 and wk 5), six pigs of each treatment x genotype group were placed in a large respiration chamber and energy balances (in protein and fat) and metabolic rate were measured. Rate of weight gain measured over the final 6 wk of the experimental period increased by 105 g/d (13%) with rpST administration (P less than .01). Daily protein gain over 6 wk was increased by 48 g/animal with application of rpST (P less than .001). There was a genotype x treatment interaction (P less than .01) for protein gain. Daily protein gain in Durocs with pST treatment was increased (39%) more than in crossbreds (31%). Daily fat gain was decreased by 42 g/animal (P less than .001) by T. Daily heat production with rpST was increased by 12 kcal/kg.75, which is comparable to a 12% increase in the maintenance energy requirement.     

Udder health implications of premature bovine mammary regression. I. Clinical, subclinical and reducing-sugar changes in milk during 168 hours of suspended milking in mid-lactation

The investigation involved 4 mastitis-free cows, exposed to 168 h of suspended milking to induce prolonged milk stasis and premature mammary regression during mid-lactation. After 48 h the milk stasis elicited mastitis-like changes in the clinical, somatic cell count (SCC), bovine serum albumin (BSA) and beta-N-acetyl-D-glucosaminidase (NAG) characteristics of the udder secretions. Such changes in secretions from non-mastitic regressive mammary glands raise doubts about the present knowledge, definition, and diagnosis of so-called non-specific or aseptic mastitis. Determinations of fluctuating lacteal concentrations of lactose, galactose, mannose and glucose suggest that the secretory epithelium altered its metabolism and integrity in response to the intramammary perturbation by following a certain pattern of regressive adjustments which: (i) were apparently triggered during the initial 24 h of perturbation by disturbed Na-K-ATPase activities, followed by a cascade of changes in ion regulation, carbohydrate metabolism and increased formation of lactic acid as a metabolic end-product; (ii) advanced in a stepwise fashion during 0-24, 24-72 and 72-168 h of perturbation from recognition response to alarm reactions and manifestation of regression respectively; (iii) showed that markedly decreased carbohydrate levels preceded major increases of the SCC, BSA and NAG values; (iv) indicated that after 72 h of milk stasis leucocytic infiltrations sharply increased the SCC to more than 500,000 per ml and accelerated the manifestation of regression. The results of this study imply that extensive premature regression of healthy, and especially, pre-irritated udders could have significant implications for the development of different types of bovine mastitis during lactation and should be further investigated.     

Relationship between oocyte maturation and fertilization on zygotic diversity in swine

Two experiments were conducted to examine how oocyte maturation and fertilization influence zygotic diversity in swine. In the first experiment, the distribution of oocyte maturation was compared to that of zygotic development. Oocytes were aspirated from follicles of 31 gilts and classified into stages of meiosis. Zygotes were flushed from oviducts of 19 additional gilts and classified into stages of meiosis and fertilization. The second experiment examined whether the time from ovulation to fertilization was constant among all oocytes. To test this premise, four to six oocytes from follicles of 10 mated gilts were aspirated just before or during ovulation, stained and transferred back into the oviducts of these same gilts. Zygotes were recovered 10 h later to determine whether the first oocytes ovulated were the more developed zygotes and, conversely, whether the last oocytes to be ovulated represented the lesser developed contemporaries. The skewed (P less than .05) distribution of oocyte maturation was similar to that of zygotic development. Regression of the frequency distribution describing early oocyte maturation resulted in a line with a slope (.59) that was similar to the slope (.58) of the regressed distribution of zygotic development. Likewise, the order of ovulation and order of subsequent stages of zygotic development were similar. These data suggest that variation in zygotic development in swine was due to variability in oogenesis; the time from ovulation to fertilization appeared to be constant.     

The development of a transport and enrichment medium for Campylobacter fetus

A transport and enrichment medium was developed for Campylobacter fetus. From inocula of between 10 and 35 organisms the medium was able to support the multiplication of 19 of 21 strains of C. fetus if the medium was incubated immediately after inoculation; when incubation was delayed for 3 days after inoculation, only seven of the 21 strains multiplied. From inocula of 100-350 organisms all 21 strains multiplied following immediate incubation, and 20 of 21 when incubation was delayed for 3 days. From inocula of about 10(4) organisms all strains multiplied following immediate or delayed incubation. The medium restricted the growth of Proteus vulgaris and Pseudomonas aeruginosa.     

Clinical use of epidural xylazine in the horse

Xylazine was administered into the epidural space of nine horses to facilitate various perineal manipulations (ie rectovaginal laceration repair, replacement of prolapsed rectum and urethral extension). The resulting caudal analgesia was sufficient for all procedures. The duration of analgesia from a single injection of epidural xylazine (0.17 to 0.22 mg/kg bodyweight) was at least 3.5 h. No horses were ataxic during or after the treatment. This trial demonstrates that xylazine given into the epidural space of horses provides prolonged regional analgesia which is sufficient for clinical use.     

Nucleotide sequence of hog cholera virus RNA: properties of the polyprotein encoded by the open reading frame spanning the viral genomic RNA

Hog cholera virus RNA was cloned and sequenced. A single major open reading frame (ORF), encoding an amino acid sequence of 3898 residues, was found in the second reading frame of the sequence of one of the cDNA strands. We demonstrated that the ORF spans the length of the viral sense RNA, which implies that it is translated into a precursor polyprotein. Several properties of this polyprotein, like hydrophobicity, position of putative protease cleavage sites, distribution of N-linked glycosylation sites, distribution of cysteines and distribution of acidic and basic residues are described and discussed.     

Enteral nutrition by tube

When oral intake is unsatisfactory or contraindicated, maintenance of nutrition by tube feeding is an alternative to the parenteral route. A large volume of research data supports the decision to use the enteral route whenever possible. Entry of food into the alimentary tract is a stimulus to structural and functional maintenance of that tract. Enteral nutrition can be given via indwelling nasoesophageal, pharyngostomy, esophagostomy, percutaneous or surgical gastrostomy, or enterostomy tube. Use of an appropriate catheter, familiarity with the technique used, and careful patient selection and monitoring are important factors in successful tube feeding. Blenderized pet food diets should be fed whenever possible; commercially available liquid diets provide an alternative when tube caliber or patient factors preclude the use of blenderized foods.     

The pathogenesis of velogenic Newcastle disease virus infection of chickens of different ages and different levels of immunity

Chickens of 7 weeks or 20 weeks of age were divided into three groups according to their antibody status (high, low, absent) and were infected with a velogenic viscerotropic Newcastle disease virus. To follow patterns of viral replication, birds were necropsied at regular intervals up to 22 days and organs were sampled from each bird. In non-immune birds, virus could be isolated from all organs examined. In birds with antibody, virus was most frequently isolated from the proventriculus, cecal tonsil, bursa, and brain. However, because no one organ could be recommended for all situations, all four should be sampled for field diagnosis. In immune birds, although clinical signs were either mild or absent, widespread virus replication occurred up to 19 days post-challenge.